#!/usr/bin/env python
# @FileName :1.14练习1.py
# @Time :2024/1/14 11:39
# @Author :huya
str1 = input("请输入一串字符：")
count = 0
for i in str1:
    if(i=='a'):
        count+=1
print(f"您输入的字符是：{str1} 其中a的个数有{count}个")